Not quite, Rocky. August was called Sextilis (from 6) and I don't recall July's former name. It wasn't inserting two months that messed it up, because there was no insertion; the months were just renamed. The numbers are off because the year used to start around the beginning of spring, March 25. (This remained true in England until 1752!)

Yes, the day after March 24, 1700 was March 25, 1701 under that system, and yes, that is just... fucked up by our standards.